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1.
Histochem Cell Biol ; 154(1): 7-20, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32372108

RESUMO

Molecular pathology allows the identification of causative agents in infectious diseases and detection of biomarkers important for prediction of disease susceptibility, diagnosis and personalized therapy. Accordingly, nucleic acid-based methods have gained a special role in clinical laboratories particularly to evaluate solid and hematological tumors. Extraction of nucleic acids is commonly performed in microdissected formalin-fixed paraffin-embedded (FFPE) or cytological samples that had been previously evaluated through the use of hematoxylin and eosin (H&E) or Papanicolau (Pap) stains, respectively. Although the effect of both stains on nucleic acids integrity has been explored by several authors, the results are not consistent and require further examination. Accordingly, the goal of this review was to assess the influence of H&E and Pap stains on DNA and RNA integrity and to address the mechanism by which each staining compromises molecular based-analysis. The analyzed studies demonstrate that H&E- and Pap-staining result in low DNA recovery and some degree of DNA fragmentation. Additionally, it is concluded that hemalum inhibits PCR by interfering with DNA extraction, preventing DNA polymerase attachment and possibly by rescuing divalent cations. Accordingly, proper sample purification and adjustment of PCR conditions are of key importance to achieve satisfactory results by PCR in H&E- and Pap-stained samples. Furthermore, although H&E results in RNA fragmentation, it is possible to perform expression analysis in H&E-stained frozen sections, using RNase-free conditions, low amounts of hematoxylin and a rapid protocol from sample collection to RNA analysis. It The effect of Pap-staining on RNA integrity remains to be determined.


Assuntos
DNA/análise , Amarelo de Eosina-(YS)/química , Hematoxilina/química , Teste de Papanicolaou , RNA/análise , Animais , DNA/genética , DNA/isolamento & purificação , Humanos , Inclusão em Parafina , Reação em Cadeia da Polimerase , RNA/genética , RNA/isolamento & purificação , Coloração e Rotulagem
2.
RNA ; 23(11): 1712-1728, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28821580

RESUMO

The mechanistic/mammalian target of rapamycin (mTOR) is a conserved serine/threonine kinase that integrates cellular signals from the nutrient and energy status to act, namely, on the protein synthesis machinery. While major advances have emerged regarding the regulators and effects of the mTOR signaling pathway, little is known about the regulation of mTOR gene expression. Here, we show that the human mTOR transcript can be translated in a cap-independent manner, and that its 5' untranslated region (UTR) is a highly folded RNA scaffold capable of binding directly to the 40S ribosomal subunit. We further demonstrate that mTOR is able to bypass the cap requirement for translation both in normal and hypoxic conditions. Moreover, our data reveal that the cap-independent translation of mTOR is necessary for its ability to induce cell-cycle progression into S phase. These results suggest a novel regulatory mechanism for mTOR gene expression that integrates the global protein synthesis changes induced by translational inhibitory conditions.


Assuntos
Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Regiões 5' não Traduzidas , Animais , Hipóxia Celular/genética , Linhagem Celular , Evolução Molecular , Regulação da Expressão Gênica , Células HCT116 , Células HEK293 , Células HeLa , Humanos , Hidrazonas/farmacologia , Luciferases de Vaga-Lume/genética , Luciferases de Vaga-Lume/metabolismo , Biossíntese de Proteínas , Inibidores da Síntese de Proteínas/farmacologia , Capuzes de RNA/genética , Capuzes de RNA/metabolismo , Dobramento de RNA , RNA Mensageiro/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Pontos de Checagem da Fase S do Ciclo Celular/genética , Tiazóis/farmacologia
3.
Nucleic Acids Res ; 43(13): 6528-44, 2015 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-26068473

RESUMO

Nonsense-mediated mRNA decay (NMD) is a surveillance pathway that recognizes and selectively degrades mRNAs carrying premature termination codons (PTCs). The level of sensitivity of a PTC-containing mRNA to NMD is multifactorial. We have previously shown that human ß-globin mRNAs carrying PTCs in close proximity to the translation initiation AUG codon escape NMD. This was called the 'AUG-proximity effect'. The present analysis of nonsense codons in the human α-globin mRNA illustrates that the determinants of the AUG-proximity effect are in fact quite complex, reflecting the ability of the ribosome to re-initiate translation 3' to the PTC and the specific sequence and secondary structure of the translated ORF. These data support a model in which the time taken to translate the short ORF, impacted by distance, sequence, and structure, not only modulates translation re-initiation, but also impacts on the exact boundary of AUG-proximity protection from NMD.


Assuntos
Códon sem Sentido , Degradação do RNAm Mediada por Códon sem Sentido , Biossíntese de Proteínas , RNA Mensageiro/química , Animais , Linhagem Celular Tumoral , Códon de Iniciação , Humanos , Camundongos , Fases de Leitura Aberta , Iniciação Traducional da Cadeia Peptídica , alfa-Globinas/genética , Globinas beta/genética
4.
Biomed Pharmacother ; 172: 116251, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38330709

RESUMO

Gastric Cancer (GC) is one of the most prevalent cancers worldwide. As the currently available therapeutic options are invasive, new and more benign options are being explored. One of which is Apigenin (Api), a natural flavonoid found in fruits and vegetables, such as celery, parsley, garlic, bell pepper and chamomile tea. Api has known anti-inflammatory, -oxidant, and -proliferative proprieties in several diseases and its potential as an anticancer compound has been explored. Here we systematize the available data regarding the effects of Api on GC cells, in terms of cell proliferation, apoptosis, Helicobacter pylori (H. pylori) infection, and molecular targets. From the literature it is possible to conclude that Api inhibits cell growth in a dose- and time-dependent manner, which is accompanied by the reduction of clone formation and induction of apoptosis. This occurs through the Akt/Bad/Bcl2/Bax axis that activates the mitochondrial pathway of apoptosis, resulting in restriction of cell proliferation. Additionally, it seems that the anti-proliferative potential of Api on GC cells is particularly relevant in a more aggressive GC phenotype but can also affect normal gastric cells. This indicate that this flavonoid must be used in low-to-moderate doses to avoid side-effects induced by disturbance of the normal epithelium. In H. Pylori-infected cells, the literature demonstrates that Api reduces inflammation by diminishing the levels of H. pylori colonization, by preventing NF-kB activation and by diminishing the production of reactive oxygen specimens (ROS). Accordingly, in GC Api seems to regulate different hallmarks of cancer, such as cell proliferation, apoptosis, cell migration, inflammation and oxidative stress, demonstrating its potential has an anti-GC compound.


Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/tratamento farmacológico , Apigenina/farmacologia , Apoptose , Antioxidantes , Inflamação
5.
Toxics ; 10(7)2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35878307

RESUMO

Emerging contaminants such as nanoplastics (NPs), as well as manufacturing by-products such as plasticizers, have gained global attention and concern due to their limited biodegradability and their potential impact on human health, in particular the effects on respiratory tissue. In parallel, in vitro cell culture techniques are key to the assessment and characterization of toxic effects and cellular mechanisms in different types of tissues and should provide relevant information to understand the hazardous potential of these emergent contaminants. This systematic review presents the main results on the current knowledge of the effects of NPs and plasticizers on lung cells, as assessed with the use of in vitro cell culture techniques. From the selected studies (n = 10), following the PRISMA approach, it was observed that cell viability was the most frequently assessed endpoint and that most studies focused on epithelial cells and exposures to polystyrene (PS). It was observed that exposure to NPs or plasticizers induces cytotoxicity in a dose-dependent manner, regardless of the size of the NPs. Furthermore, there is evidence that the characteristics of NPs can affect the toxic response by promoting the association with other organic compounds. As such, further in vitro studies focusing on the combination of NPs with plasticizers will be essential for the understanding of mechanisms of NPs toxicity.

6.
Toxics ; 10(6)2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35736920

RESUMO

According to the WHO, air quality affects around 40 million people, contributing to around 21,000 premature deaths per year. Severe respiratory diseases, such as asthma and chronic obstructive pulmonary disorder, can be promoted by air pollution, which has already been documented; this is one of the reasons why air quality is a very relevant factor for human health and well-being. Aerosols are an aggregation of solid or liquid particles dispersed in the air and can be found in the form of dust or fumes. Aerosols can be easily inhaled or absorbed by the skin, which can lead to adverse health effects according to their sizes that range from the nanometre to the millimetre scale. Based on the PRISMA methodology and using the Rayyan QCRI platform, it was possible to assess more than four hundred research articles. This systematic review study aimed to understand the impact of particles on pulmonary endothelial cells, namely particulate matter in different sizes, cigarette smoke, diesel exhaust particles and carbon black. The main conclusions were that particles induce multiple health effects on endothelial cells, namely endothelial dysfunction, which can lead to apoptosis and necrosis, and it may also cause necroptosis in lung structure.

7.
Poblac. salud mesoam ; 18(2)jun. 2021.
Artigo em Inglês | LILACS, SaludCR | ID: biblio-1386917

RESUMO

Abstract: Objective: Carry out a spatial-temporal characterization of the incidence of tuberculosis (TB) in Maputo, Mozambique. Method: a descriptive ecological study of tuberculosis cases reported in an information system. The annual mean incidence rate and the number of TB notification cases in the municipality of Maputo from 2011 to 2016 were analyzed. Descriptive statistics were used with calculations of measures of central tendency (mean) and an application of the Poisson linear regression model. Trimester notifications were stratified by district, clinical form, and age group. The quarterly average temperature of the evaluated area was added as a covariate in the model seasonal. Results: 34,623 TB cases were notified from 2011 to 2016, with a trimester average of 1,443 cases. The average annual incidence was higher in the Kampfumo district, with 909.8 per 100 thousand inhabitants (95% CI 854.1 - 968.2); almost twice as much as the incidence of the municipality of Maputo, 527.8 (95% CI 514, 3-541.6), and the country of Mozambique, 551 (95% CI 356 - 787). The clinical diagnosis of the tested cases was higher concerning the bacteriological diagnosis; 44%, and 35%, respectively. Conclusion: Maputo had similar incidence rates to the country of Mozambique, however, there was a heterogeneity rate by district and a reduction in the number of TB cases in both the general population (not co-infected with HIV) and those over 15 years old, being higher in the first trimester.


Resumen: Objetivo: realizar una caracterización espacio-temporal de la incidencia de tuberculosis (TB) en Maputo, Mozambique. Método: estudio ecológico descriptivo de casos de tuberculosis reportados en un sistema de información. Se analizó la tasa de incidencia media anual y el número de casos de notificación de TB en el municipio de Maputo entre 2011 y 2016. Se utilizó estadística descriptiva para calcular las medidas de tendencia central (media) y la aplicación del modelo de regresión lineal de Poisson Las notificaciones trimestrales se estratificaron por distrito, forma clínica y grupo de edad. Resultados: se notificaron 34,623 casos de TB entre 2011 y 2016, con un promedio trimestral de 1,443 casos. La incidencia anual promedio fue mayor en el distrito de Kampfumo, 909.8 por cada 100 mil habitantes (IC 95% 854.1 - 968.2), casi el doble que la incidencia del municipio de Maputo, 527.8 (IC 95% 514 , 3-541.6), y el país de Mozambique, 551 (95% CI 356 - 787). El diagnóstico clínico de los casos fue mayor en relación al diagnóstico bacteriológico, 44% y 35%, respectivamente. Conclusión: Maputo tuvo tasas de incidencia similares a las del país, sin embargo, hubo una heterogeneidad en las tasas por distrito y una reducción en el número de casos de TB en la población general (no coinfectados con VIH) y en los mayores de 15 años, siendo mayores en el primer trimestre.


Assuntos
Humanos , Tuberculose/epidemiologia , Análise Espaço-Temporal , Saúde Pública , Moçambique
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